H02N2/026—Electric machines in general using piezo-electric effect, electrostriction or magnetostriction producing linear motion, e.g. actuators; Linear positioners ; Linear motors by pressing one or more vibrators against the driven body

H—ELECTRICITY

H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER

H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR

H02N2/00—Electric machines in general using piezo-electric effect, electrostriction or magnetostriction

H02N2/0005—Electric machines in general using piezo-electric effect, electrostriction or magnetostriction producing non-specific motion; Details common to machines covered by H02N2/02 - H02N2/16

H02N2/001—Driving devices, e.g. vibrators

H02N2/002—Driving devices, e.g. vibrators using only longitudinal or radial modes

H—ELECTRICITY

H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER

H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR

H02N2/00—Electric machines in general using piezo-electric effect, electrostriction or magnetostriction

Abstract

The invention relates to an ultrasonic linear motor (1) comprising a plate-type ultrasonic oscillator (2) with two planar parallel main faces, two end faces and two lateral faces and a displaceable element (9) that engages with at least one guide rail (10) and has two friction parts, said element interacting with the ultrasonic oscillator to cause friction via the lateral faces of the friction parts. The lateral faces of the ultrasonic oscillator are planar and are inclined at the same angle in relation to a longitudinal plane of symmetry, in such a way that the intersection lines between the planes of the lateral faces and the longitudinal plane of symmetry run parallel to the main faces of the ultrasonic oscillator. The friction parts of the displaceable element are interconnected by springs.

Description

Translated from German

Die Erfindung betrifft einen Ultraschalllinearmotor und kann in preiswerten optischen Präzisionssystemen oder ähnlichen Geräten eingesetzt werden. The invention relates to an ultrasonic linear motor and can be used in inexpensive precision optical systems or similar devices.

Bekannt sind Ultraschalllinearmotoren mit als Plättchen ausgeführten Ultraschalloszillatoren, auf denen das Friktionselement befestigt ist (siehe zB are known ultrasonic linear motors designed as a plate ultrasonic oscillators on which the friction element is fixed (see, for exampleEP 1 267 425 A EP 1267425 A). ).Dabei ist eine Anpressvorrichtung so ausgeführt, dass die am Friktionselement anliegende Kraft vollständig auf das lineare Kugellager des beweglichen Elementes übertragen wird. In this case, a pressing device is designed such that the friction force is applied to the transferred completely to the linear ball bearing of the movable member.Dadurch steigen die Reibungsverluste und es ist nicht möglich, preiswerte Gleitlager in solchen Motoren einzusetzen. This increases the friction losses and it is not possible to use inexpensive plain bearings in such motors.

Nachteilig bei diesen Motoren ist, dass der Oszillator kompliziert in der kon□struktiven Ausführung und deswegen teuer in der Herstellung ist. A disadvantage of these engines that the oscillator complicated □ in the kon constructive design and therefore expensive to manufacture.Die Motoren können in preiswerten optischen Systemen eingesetzt werden. The motors can be used in low-cost optical systems.Jedoch sind sie ungenau in der Positionierung des beweglichen Elementes, und es ist nicht möglich, sie beliebig zu verkleinern. However, they are inaccurate in the positioning of the movable element, and it is not possible to reduce it as desired.

Die Erfindung schließt den wesentlichen Gedanken ein, einen als solchen bekannten plattenförmigen Ultraschalloszillator in einer Anordnung mit einem beweglichen Element, welches zwei Friktionsteile aufweist und in Eingriff mit einer Führungsschiene steht, in eine geeignete Kraft-Konstellation bezüglich dieser Führungsmittel zu bringen. The invention includes the essential idea, a process known as such a disc-shaped ultrasonic oscillator in an assembly with a movable element having two friction parts, and is engaged with a guide rail to be brought into a suitable force constellation with respect to said guide means.Hierbei ist es durch Wahl der Plattenform und der Konstruktion des beweglichen Elementes möglich, einen Teil der Anpresskraft der Friktionselemente an die Oberflächen des ausgeführten Oszillators auch zum Anpressen des beweglichen Elementes des Motors an seine Führung einzusetzen. It is possible by selection of plate shape and the structure of the movable member, also use part of the contact pressure of the friction elements to the surfaces of the oscillator executed for pressing the movable member of the motor to its guide.

Die Erfindung schließt weiter den Gedanken ein, eine federnde Verbindung zwischen den genannten Friktionsteilen vorzusehen, die eine geeignete Anpresskraft des beweglichen Elementes an die Seitenflächen des Ultraschalloszillators bereitstellt. The invention further includes the concept of providing a resilient connection between said Friktionsteilen that provides a suitable contact pressure of the movable member to the side surfaces of the ultrasonic oscillator.Des weiteren wird hierdurch eine geeignete Anpresskraft zwischen dem beweglichen Element und der erwähnten Führungsschiene bereitstellt. Further, thereby a suitable contact force between the movable member and the said guide rail is provides.Schließlich gehört zur Erfindung der Gedanke, die erwähnten Anpresskräfte durch eine geneigte Ausführung der Seitenflächen des Ultraschalloszillators in eine vorbestimmte Relation zueinander zu bringen. Finally, the invention includes the idea to bring the mentioned contact pressure by an inclined design of the side surfaces of the ultrasonic oscillator in a predetermined relation to each other.

In einer weiteren Ausführungsform ist vorgesehen, dass die Führungsschiene klammerartig ausgeführt und fest mit einer gemeinsamen Elektrode des Ultraschalloszillators verbunden ist. In a further embodiment it is provided that the guide rail carried out clamp-like and is fixedly connected to a common electrode of the ultrasonic oscillator.Dies vereinfacht die Konstruktion des Miniaturmotors. This simplifies the construction of the miniature motor.

Die Hauptflächen des Ultraschalloszillators sind in einer zweckmäßigen Ausführung rechteckig ausgebildet, und in einer weiteren Ausführung gilt dies auch für die Seitenflächen. The major faces of the ultrasonic oscillator are rectangular in an expedient embodiment, and in another embodiment, this also applies to the side surfaces.

Die federnde bzw. elastische Verbindung der Friktionsteile des beweglichen Elementes miteinander wird in einer zweckmäßigen Ausführung durch eine Druckfeder realisiert, welche die Friktionsteile gegeneinander elastisch vorspannt. The resilient or elastic connection of the friction parts of the movable member to each other is realized in a preferred embodiment, by a compression spring which biases the friction parts against each other elastically.Auch diese Druckfeder ist in einer Ausgestaltung dieser Ausführung klammerartig ausgeführt, wobei die Friktionsteile an den freien Enden der Schenkel der Klammer platziert sind. These compression spring is designed like a clamp in one aspect of this embodiment, wherein the friction parts are placed at the free ends of the legs of the staple.

Claims (6)

An ultrasonic linear motor (1), comprising a plate-type ultrasonic oscillator (2) with two planar parallel main faces, two end faces and two lateral faces, and a mobile element (9) engaged with at least one guide rail (10) and having two friction parts (11, 12), said element frictionally interacting with the ultrasonic oscillator (2) via the lateral faces of the friction parts (11, 12),characterized in that
the lateral faces (7, 8) of the ultrasonic oscillator are planar and are inclined at like angles in relation to a longitudinal plane of symmetry (19) in such a way that the intersection lines between the planes of the lateral faces (7, 8) and the longitudinal plane of symmetry extend parallel to the main faces of the ultrasonic oscillator, and that the friction parts (11, 12) of the mobile element (9) are resiliently connected to each other, wherein the friction parts (11, 12) of the mobile element (9) press against the corresponding lateral faces (7, 8) of the ultrasonic oscillator (2) with a first contact pressing force and the mobile element (9) presses against the guide rail (10) with a second contact pressing force, wherein the ratio between the first and second contact pressing forces is determined by the angle of inclination of the lateral faces (7, 8) in relation to the longitudinal plane of symmetry (19) of the ultrasonic oscillator (2).

The ultrasonic linear motor according to claim 1,characterized in that
connection electrodes of the ultrasonic oscillator comprise elastic, thin, conductive rods, the one end of which is firmly connected to the corresponding electrodes and the other end of which is firmly fixed in relation to the guide rail.

The ultrasonic linear motor according to claim 2,characterized in that
the guide rail is realized in a clamp-type manner and is firmly connected to a common electrode of the ultrasonic oscillator.

The ultrasonic linear motor according to one of the preceding claims,characterized in that
the friction parts of the mobile element are connected to each other by a compression spring element and are elastically biased against each other.

The ultrasonic linear motor according to claim 4,characterized in that
the compression spring element is realized in a clamp-type manner, with the friction parts being placed at the free ends of the legs of the clamp.

The ultrasonic linear motor according to one of the preceding claims,characterized in that
the main faces and/or the lateral faces of the ultrasonic oscillator are rectangular.